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Home >> Infiniti >> 2024 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (2 Of 2) >> Component /Circuit Diagnosis >> Refrigerant Pressure Sensor >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT 
    1. Disconnect refrigerant pressure sensor harness connector.
    2. Turn ignition switch ON.
    3. Check the voltage between refrigerant pressure sensor harness connector and ground.
      Refrigerant pressure sensor Ground Voltage (V)
      Connector Terminal
      E77 1 Ground Approx. 5

    Is the inspection result normal?

    YES>>

    GO TO 3.

    NO>>

    GO TO 2.

  2. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness for open or short between ECM and refrigerant pressure sensor
    • Loose or poor connection for each connector and harness

    >>

    Repair open circuit, short to ground or short to power in harness or connectors.

  3. CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between refrigerant pressure sensor harness connector and ECM harness connector.
      Refrigerant pressure sensor ECM Continuity
      Connector Terminal Connector Terminal
      E77 3 F91 13 Existed
    4. Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES>>

    GO TO 5.

    NO>>

    GO TO 4.

  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness for open or short between ECM and refrigerant pressure sensor
    • Loose or poor connection for each connector and harness

    >>

    Repair open circuit, short to ground or short to power in harness or connectors.

  5. CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check the continuity between refrigerant pressure sensor harness connector and ECM harness connector.
      Refrigerant pressure sensor ECM Continuity
      Connector Terminal Connector Terminal
      E77 2 F91 12 Existed
    2. Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES>>

    GO TO 7.

    NO>>

    GO TO 6.

  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness for open or short between ECM and refrigerant pressure sensor
    • Loose or poor connection for each connector and harness

    >>

    Repair open circuit, short to ground or short to power in harness or connectors.

  7. CHECK INTERMITTENT INCIDENT 

    Refer to Inspection .Is the inspection result normal?

    YES>>

    Replace refrigerant pressure sensor. Refer to REFRIGERANT PRESSURE SENSOR : Removal and Installation .

    NO>>

    Repair or replace malfunctioning part.

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